New approaches to assessment of older workers are necessitated by changes in mandatory retirement legislation. The proposed longitudinal study will investigate the relationship between assessed intellectual abilities and job performance in three age groups at two times of testing. The proposed study will be carried out at the headquarters of a non-profit aerospace research corporation in the Los Angeles area. Subjects will be highly educated technical employees in three divisions. Assessment measures will be selected and/or designed to provide indices of the underlying skills required for high-level performance. Verbal, reasoning, memory, spatial, and flexibility skills will be tested. Paper-and-pencil measures will be those previously demonstrated to be effective in use with older groups. A series of measures developed for use with all aged populations will also be used. A portable microprocessor system will provide for accurate, systematic administration of the new measures and for the collection, storage and analyses of accuracy and rate of response data. Performance assessment measures being developed by the firm will serve as the primary criterion measures. Relative change in the relationship between skills and job performance over a short-term longitudinal period will serve as the major dependent variable. Change in skills will be used to compare retired and non-retired employees. Older employees and their employers are expected to benefit from use of the proposed procedures. While performance assessment will be a critical factor in deciding who continues to work, those employees who wish to continue working although their assessed work performance no longer meets acceptable criteria will be able to demonstrate skills which may be required for other positions in the firm. Employers will be assured of the skills of their older employees and will be able to place those individuals in positions where their skills may be used to the best advantage. This project is expected to serve as a model for other highly technically oriented firms.